Communication system



May 27, 1941. R. H. CAMPBELL 2,243,692

COMMUNICATION SYSTEM -FiledMarch 25, 1940 Patented May 27, 1941 CoMMUNIcA'rroN SYSTEM Richard H. Campbell, Racine, Wis.,v assignor to Webster Electric Company, Racine, Wis., a corporation of Delaware Application March 25, 1940, seriai No. 325,670

6 Claims.

The present invention relates to communication systems and has for its primary object the provision of an improved system for disseminating information from what may be termed an information center to a plurality of outlying substations. l

In department stores, banks, and otherestablishments of similar nature, records of transactions,v etc., are ordinarily kept at a central locacation distant from places where .the information is required in a multitude of everyday transactions. Various arrangements have been perfected in the past for making the information available, but they have been open to objections of one sort or another.

'Ihe present invention has for its object the provision of a system whereby information from a central location maybe disseminated readily and Vquickly to outlying locations upon request.

A further object of the present invention is to provide a system that is continuously conditioned for instantaneous operation and one in which a personat a substation has merely to pick up a combined receiver and microphone to place himself in communication with a person at the information center.

. A further object of the invention is so to arrange the system that only the operator at a substation can hear the information sent from the information center, and the person at the information center may hear and speak even when at a considerable distance from that portion of the apparatus forming the system located at the center.

A further object of the invention is to provide a system wherein each substation is provided with a busy signal and with means for rendering operative all the busy signals whenever the particular substation is placed in communication with the information center.

Other objects and advantages ci the invention will become apparent from the ensuing description in the-course of which reference is made to the accompanying drawing, the single figure of which schematically represents one embodiment of the invention.

Referring now to this figure, the information center is indicated by reference character l and the outlying substations by reference characters 2 and 3. Only two substations are illustrated, but the system may comprise any number, as will appear more fully hereinafter. For thelpurpose' of better describing the invention, itis assumed that the infomation center is the credit record room of a department store, and the substations 2 and 3 are department managers oiiices or desks.

The apparatus at the information center is of a type conditioned for instantaneous operation and comprises a microphone I0 and a loudspeaker i2 connected, respectively, to the input and output of amplifiers I4 and I6. The amplifiers are preferably, but not necessarily, conditioned for instantaneous operation; i. e., they are normally supplied with power from a source not shown. The microphonel and loudspeaker are so constructed and arranged with respect to the ampliers that a person located anywhere in the information center, which may be a room or a portion of a room where the records are kept, may speak in a normal toneof voice and be heard by persons at the substations and may hear what information is desired. The amplifiers, however, need not be located directly at station I, as illustrated-they may be located at some convenient central location.

The information center is connected to the substations through incoming and outgoing circuits.

. The former consists of a conductor i8 and a common conductor 20 (which may be a grounded shield for the other conductors), and the latter of conductor 22 and the common conductor 20.

substations 2 and 3 are each provided with two switches, one for controlling the connections of the voice receiving and transmitting means thereat to the amplifiers at the information center and partly completing an energizing circuit.

for busy signal means, and the second for completing the energization of the busy signal means. Thus, substation 2 is provided with a communication circuit and busy signal circuit controlling switch 24 of the normally open push button type and a signal circuit controlling normally open switch 23 actuated by a translating device 23. Identical switches 3U and 32 are provided at substation 3, and at any other stations which may be included in the system.A Switch 32, like switch 26, is actuated by a translating device 34. The signal devices preferably take the form of electric lamps 35.

Before proceeding with a detailed discussion of the circuits, it may be well to point out that the translating devices 28rand 34.at substations 2 and. 3, respectively, comprise receivers 33 and 38 and transmitters or microphones 4i) and 42. The translating devices 28 and 34 preferably take a form resembling that of the ordinary telephone l handset and when not in use may be placed upon suitablev supports, not shown, and when so supportedmaintain the switches 2E and 32 in the open circuit positions in which they are illustrated. When the translating devices are picked up for use, the switches are automatically closed.

The combined communication and signal circuit controlling switch 24 at substation 2 normally occupies a position such that the receiver 36 and microphone 40 are disconnected from their respective ampliers and the signal control circuit is broken. The switch is operable manually to a displaced position to connect the receiver 36 to the output of amplifier I4 and microphone 40 to the input of amplifier I6, and also to condition the signal control circuit for closure vbyswitch 26. Receiver 36 is connected to `the output of amplifier I4 by movable switch blade 44, microphone 49 is connected to the input of amplier I6 by a second movable switch blade 46, and the signal circuit is conditioned for closure `by switch 26 by a third movable switch blade 48. rIhe movable switch blades 44, 46 and 48 are operable simultaneously by a push button 56, as clearly indicated in the drawing.

'I'ne receiver 36 is connected to the output of ampliiier I4 through a circuit, including the amplifier output conductor 22, a branch conductor 52 leading to substation 2, movable vswitch blade 44, a conductor 54 leading to the receiver, and thence back to the amplier output through conductors 5S, 58 and the previously mentioned common conductor 2i).

The microphone 48 is connected to the input of amplifier I5 through a circuit including the amplier input conductor I8, a branch conductor 68, movable switch blade 46, a conductor 62 leading to the microphone, and thence back to the amplifier input through conductor 64 and the previously mentioned conductors 58 and 26. The signal circuit is conditioned for closure by switch 26 through a circuit including a local source cf power, illustrated as a battery 66, located at some suitable central location, a signal circuit controlling solenoid 68, conductor JD, movable switch blade 48, a conductor 'l2 leading therefrom to switch 26, and conductor 'I2 leading from the latter back to the battery.

Thus, whenever switch 24 is depressed and the translating device V28 is picked up for use, stations I and 2 are connected for two-way communication and the signal circuit controlling solenoid 68 energized.

The energization of solenoid 63 results in the supply of power to the lamps 35 from a suitable source, not shown, through conductors 'I4 and a normally open switch 15, closed upon energization of solenoid 68. knected in parallel so that all are supplied with power simultaneously. The lamp 35 at substation 2 is connected to the power supply by conductors 'I8 and the lamp 36 at substation 3 by conductors BIJ, the lamps atother stations, not shown, by conductors 82. y

The apparatus at substation 3 is connected in parallel to the apparatus atV substation 2 so that when the switch 38 at substation .3 is depressed and the translating device 34 thereat is picked up, the receiver 38 is connected to the output of ampliiier I4, microphone 42 is connected to the input of amplifier I6 and the signal circuit controlling solenoid is energized to supply energy to the signal lamps V35 at the various substations.

Receiver 38 is connected to the outputvof amplifier I4 through a circuit including the output conductor 22, branch conductor 84, movable switch blade 860i the push button switch 38, and'conductor S6 leading to receiver 38, and

The lamps 35 are all conifrom thence back to the amplifier output through conductors 88, 90, and the previously mentioned common conductor 2D. The microphone 42 is connected to the input of amplifier I6 through a circuit including input conductor I8, branch conductor 92, movable switch blade 94 of the push button switch 30, and conductor 86 to the microphone, and from thence back to the input through conductor 98 and the previously mentioned conductors 90 and 20. The signal circuit controlling solenoid 68 is energized through a circuit including the battery 66, the solenoid winding 68, conductor |00 leading to the third movable switch blade |02 of push button switch 30, conductor |04 leading from the latter to switch 32, and conductor |66 leading from this switch back to the battery 66.

The remaining stations of the system, which have not been illustrated, are connected in parallel with substations 2 and 3 through branch conductors |08, H0 and II2 forming part of the interstation communication circuits; conductors H4 and `I I6 forming part `of 'the signal control circuit; and the previously-mentioned conductors 82 through which the lamps are supplied with energy.

Under normal conditions and when the system is not being utilized for thetransmission oir-'communication, the various switches assume the positions in which they are indicated, and the amplifiers I4 and I6 .are supplied with power so that any remote stations may communicate with the information center merel-y by depressing the push button switch thereat and pickingup the translating device. It may be remembered that it was assumed that the information center was locatedin a record room of a department store and the substations 2 and 3 were located at the `offices or desks of department managers'. If the department manager 'at substation -2 desires some information from the credit room, he depresses the push button switch '24 `and picks up the transiating device (or vice versa, for that matter), thereby .placing the 'microphone and receiver at the substation in direct communication with the microphone and :receiver at the credit room through the amplifiers '.14 and I6, through circuits that have been previously traced in detail. Simultaneously, the lamps at all the substations are supplied with power throughipreviously traced circuits to give Van indication that the system is in use. The Vvother department managers will, therefore, not try to communicate with the credit room as long as the lampsfare energized.

However, no harm is occasioned even V'if .two of the credit managers try to vcon'xn'umicatel with the credit room at the same time.

While only a single embodiment ofthe invention has been illustrated and described, it should; be understood that it is susceptible of other Iand furtherrnodiiications.r For instance, certain-features of the invention are wadapted for use in systems in which different types of receiving and transmitting means are used `and wherefdifferent types of interstation circuits are-utilized, It should be understood further that. the specific embodiment is not intended tolimit the scope ofY the-(invention in any way. I What I claim is new and wishftofsecure by United States -LettersPatent is, as -follows.;

1. In a communication system, the coulziinaf. tion including, .a pair `o'fampliers each' having4 anv input and an output, a station havinga loudof said amplifiers, and a microphone connected to the input of the second of said amplifiers, a plurality of substations remote from the first station, receivers and microphones at each of said substations, a pair of interstation circuits leading from said first station to said substations and connected to the input and output oi said first and second amplifiers, respectively, and means including normally open switches at each substation for connecting the microphones and receivers thereat to the input of the first amplifier and output of the second amplifier, respectively, through said interstation circuits.

2. In a communication system, the combination including, a pair of normally operative ampliiiers each having an input and an output, a station having a loudspeaker connected to the output of a first of said amplifiers and a microphone connected to the input of the seco-nd of said amplifiers, a plurality of substations remote from the first station, receivers and microphones at each of said substations, a pair of interstation circuits leading from said first station to said substations and connected to the input and output of said rst and second amplifiers, respectively, and means including normally open push button switches at each substation for connecting the microphones and receivers thereat to the input of the first amplifier and output of the second amplifier, respectively, through said interstation circuits.

3. In a communication system, the combination including, a pair of ampliiiers each having an input and an output, a station having a loudspeaker connected to the output of a rst amplifier and a microphone connected to the input of the second amplifier, a second station remote from the rst station, a translating device including a receiver and a microphone, signal means and a signal circuit at the second station, an interstation communication circuit, a manually operable normally open communication circuit and signal circuit controlling switch at the second station operable to a displaced position to connect the microphone to the input of vsaid rst amplifier and the receiver to the output of said second amplifier through said interstation circuits, and to condition said signal circuit for closure, and a normally open signal circuit completing switch at the second station operable by said translating device.

4. In a communication system, the combination including, a pair of normally operative ami plifiers each having an input and an output, a

station having a loudspeaker connected to the output of a first amplifier and a microphone connected to the input of the second amplifier, a second station remote from the iirst station, a translating device of the telephone type including a receiver and a microphone, signal means and a signal circuit at the second station, an interstation communication circuit, a manually operable normally open communication circuit and signal circuit controlling switch at the' second station operable to a displaced position to connect the microphone to the input of said first amplier and the receiver to the output of saidsecond amplifier through said interstation circuits, and to condition said signal circuit for closure, and a normally open signal circuit completing switch at the second station operable by said translating device.

5. In a communication system, the combinaion including, a pair of amplifiers each having an input and an output, a station having a loudspeaker connected to the output of a rst of said ampliers and a microphone connected to the input of a second of said amplifiers, a plurality of substations remote from said first station, translating devices including receivers and microphones at each of said substations adapted to occupy a predetermined position when not in use, interstation communication circuits, a signal circuit eXten-ding'between said substations, signal means at each substation, a normally open switch at each substation manually operable to connect the microphone thereat to the input of the first of said amplifiers and the receiver thereat to the output of the second of said amplifiers and partly to complete said signal circuits, and switch means at each substation operable by the translating device thereat when it is removed from said predetermined position for use to complete said signal circuits and render operative the signal means at all stations.

6. In a communication system, the combination inclu-ding, a pair of normally operative amplifiers each having an input and an output, a station having a loudspeaker connected to the output of a first of said ampliers and a microphone connected to the input of a second of said amplifiers, a plurality of substations remote from said first station, translating devices including receivers and microphones at each of said substations adapted to occupy a predetermined position when not in use, interstation circuits, a signal circuit extending between said substations and comprising a single solenoid, signal means at each substation operable upon energization of said solenoid, a normally open push button switch at each substation manually operable to connect the microphone thereat to the input of the iirst of said amplifiers and the receiver thereat to the output of the second of said ampliiiers and partly tocomplete said signal circuits, and switch means at each substation operable by the translating device thereat when it is moved from said predetermined position to complete a circuit to energize said solenoid and thereby render operative the signal means at all stations.

RICHARD H. CAMPBELL. 

